how to uninstall windows 8.1?

That's impossible.  You or someone else must have started it.  Windows 8.1 will never be automatically pushed to your computer unless you request it.  I'm sorry that you accidentally started it, or that someone used your computer without your permission.

You can remove it using the steps that VanCountry politely provided above.  However you are misinformed:  Windows 8.1 has no such requirement to use a Microsoft Account.  You can continue using it without that and without a password just like always, because nothing changed.

Just click "Sign In Without a Microsoft Account" at the bottom of the page:

I read this on USAToday website and since I had windows 8, it worked for me, radical, in that you reset and lose everything, so make sure.. but it got rid of the beta bugger..

A Microsoft frequently-asked-questions page about Win 8.1 explains this in conditional language that should give a reader pause: "If your PC came with Windows 8 you might be able to restore it back to Windows 8 by refreshing your PC."

Should that work, it will allow the most orderly retreat possible. Win 8's underrated "refresh" option will put a clean copy of the operating systemin place, leaving your data intact but only reinstalling apps that came bundled on the computer or were obtained through the Windows Store.

To use this option, tap or click the bottom-right corner of the desktop (or swipe in from the right edge of the Start screen), select the gear-shaped Settings icon, and then select "Change PC settings."

In that screen, click or tap "Update and recovery," choose the Recovery option and proceed with a refresh from there. The computer will use the hard drive's system-recovery partition to put things back as they were when you took the computer out of the box, plus your own data.

I have no idea why I have windows 8.1 on my laptop,except to say I turned it on one morning and it was being updated to 8.1 ,I was instructed not to turn off my computer until it was done and that is how I got 8.1 on my computer.I did not want this and do not want it now. Walter Ross

yes, it is obvious, so what's the answer, how do I uninstall 8.1?

I would very much like to know how ti uninstall windows 8.1. You want a thorough question? Windows 8.1 takes away and personal connection to the computer and requires that one goes through the microsoft team for all and any changes they wish to make to their own computer. For example, I would very much like to see and interact with my RAM and processor which in Windows 8 allowed access to any programs that slowed this down. Windows 8.1 takes this away from the individual and requires a purchase or contact with microsoft.        

Sorry, that's absolute rubbish. Please give an instance (with screen shots) as to how 8.1 no longer allows you to have access to programs that use RAM and processor cycles...